Lesson plan

# 8. Use part/part/whole diagrams to add and subtract (FP)

teaches Common Core State Standards MP1 http://corestandards.org/Math/Practice/MP1
teaches Common Core State Standards MP7 http://corestandards.org/Math/Practice/MP7
teaches Common Core State Standards 2.NBT.B.5 http://corestandards.org/Math/Content/2/NBT/B/5

# 8. Use part/part/whole diagrams to add and subtract (FP)

Lesson objective: Practice creating equations by understanding part/part/whole diagrams.

This lesson helps to build procedural skill with whole number addition and subtraction. Part/part/whole diagrams are used here because they highlight the relationship between addition and subtraction. This work develops students' understanding that we can find unknown values in addition or subtraction situations using the relationship between addition and subtraction.

Students engage in Mathematical Practice 7 as they look closely to discern a pattern or structure. The idea of structure is essential in this task as students should notice that it is always true that the parts, when combined, equal the whole when representing addition and subtraction relationships using part/part/whole diagrams.

Key vocabulary:

• equation
• part/part/whole diagram
• part
• whole

Special materials needed:

• place value tools for concrete learners